All That Glitters – Heat-Treated Gemstones

A couple of years ago, during our annual buying trip to Tucson, AZ, we noticed a trend at A LOT of gemstone booths: brilliantly-colored quartz crystals, some with vibrant aurora-borealis-type finishes. We thought they were cool from the first time we saw them, and their popularity has only grown since then — these quartz crystals continue to be one of the top-selling bead types at Blue Door Beads!

Here's just a taste of the wide variety of aura quartz we sell in the shop!

Here’s just a taste of the wide variety of quartz points we sell in the shop!

Although we have had these crystals for quite some time, it’s only been recently that people have regularly started asking us what is done to the crystals to turn them such brilliant colors. Perhaps the summer sunshine has led people to create more colorful jewelry, so they naturally gravitate toward these shimmery little guys — or maybe folks have just become more inquisitive! Whatever the reason, we soon realized that we needed to find out more about the process of creating what we have since found out is referred to as aura quartz.

Aura quartz is created through a process called vapor deposition: clear, natural quartz is heated to1600 °F in a vacuum, and then vapor from a specific mineral (see list below) is added to the chamber. The atoms from the mineral “fuse to the crystal’s surface, which gives the crystal an iridescent” metallic sheen in a wide variety of colors, depending on the mineral used. (HibiscusMoon Crystal Academy)

The International Gem Society explains in slightly more scientific terms how the process takes place, but the two most important things to keep in mind (we believe) when using/buying aura quartz are:

1.) Vapor deposition is a permanent way to “coat” a crystal. The less-than-one-micron-thick metallic coating will not chip off because the mineral has been molecularly bonded with the surface of the quartz.

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An example of rainbow aura quartz.

2.) Exposing natural crystal to such intense heat, combined with certain mineral vapors, can make the stones extremely brittle. The one exception to this fact is the variation of modified quartz called “flame quartz” or “rainbow quartz.” These quartzes “have been enhanced with a combination of titanium and gold. Titanium molecules are bonded to the quartz by the natural electrostatic charge of the crystal in a process known as magnetron ionization…since only electricity is used to deposit the titanium layers and create these colors, very little heat is involved and the integrity of the crystal is maintained.” (Wikipedia) Good to know!

Here’s a list of some of the more common types of modified quartzes, along with the various minerals that give them their distinctive colors once bonded to clear quartz:

  • Amethyst Aura Quartz (purple) –  magnesium & platinum
  • Angel Aura Quartz (bluish-silver) –  platinum and silver, but also sometimes gold or other trace metals.
  • Apple Aura Quartz (bright lime green) – nickel, which gives the stone a bright yellow-green color reminiscent of Granny Smith apples.
  • Aqua Aura Quartz (bright blue) –  gold
  • Champagne Aura Quartz (a metallic brown-gold) –– gold, iron, and platinum
  • Cobalt Aura (dark blue with an iridescent sheen) –  cobalt
  • Copper Aura Quartz (metallic copper) – Pretty self-explanatory: clear quartz bonded with copper
  • Kiwi Aura Quartz (teal green) – gold and silver, or platinum
  • Melon Aura (orange) – copper, gold, and iron
  • Opal Aura Quartz (clear with opalescent sheen) – platinum
  • Rainbow Aura (a range of colors, all with a dark iridescent sheen) – titanium and/or niobium
  • Ruby Aura (fuchsia) – made with gold, silver, and platinum
  • Sunshine Aura (bright yellow) – made with iron and/or platinum, and gold
We think amethyst aura quartz is one of the prettier varieties!

We think amethyst aura quartz is one of the prettier varieties!

Just when we think we know everything there is to know about beads, we find out about something cool like vapor deposition! Now the next time you create a piece with aura quartz and get showered with compliments (which we know you will!), you can tell you adoring fans a few fun facts about the how the aura quartz came to be!

First photo courtesy of Rachel Bleckman for Blue Door Beads.
Second photo courtesy of Crystal Vaults.
Third photo courtesy of CosmicDreamClub on Tumblr.
Information regarding different minerals bonded to quartz provided in part by Crystal Vaults.